The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:
3GPP third generation partnership project
BCCH broadcast channel
CCCH common control channel
DL downlink (node B towards UE)
IE information element
MAC medium access control
Node B base station
RACH random access channel
RRC radio resource control
UE user equipment
UL uplink (UE towards node B)
UTRA universal terrestrial radio access
UTRAN universal terrestrial radio access network
UMTS universal mobile telecommunications system
WCDMA wideband code division multiple access
Various radio technologies utilize various RACH procedures for a UE to gain contention-based access to a network. The RACH is one of multiple CCCHs, and in the UTRAN system the RACH procedure includes the UE sending an access message which includes a preamble part and a message part. The UE seeking connection to a WCDMA base station first transmits a preamble (signature sequence) on a RACH and then listens on an acquisition indicator channel AICH for a acquisition indicator AI corresponding to that preamble. If that AI is not received, the UE tries again and continues the process until it receives a corresponding AI. At that point the UE can then transmit the message part of its access message, which is also sent UL on the RACH. This message part is termed a RRC Connection Request in UTRAN.
Being on the RACH, the transport block size of the UE's RRC Connection Request message is tightly limited. Several 3GPP releases have added extensions to this message and it is now near if not at its size limit. Specifically, the maximum size of UL CCCH messages is 166 bits: the RACH transport block size (168 bits) less the size of the MAC header (2 bits). A more detailed analysis of this bit-size may be seen at document R2-105713 entitled “ANALYSIS ON RACH SIGNALLING” (3GPP TSG-RAN WG2 Meeting #71bis; Xian, China; 11-15 Oct. 2010; by Nokia Corporation and Nokia Siemens Networks), which sets forth that there are currently occasions in which the 166 bit size is too limiting.
One type of information which the UE reports on the RACH in its RRC Connection Request message is neighbor cell measurements. Consider FIG. 1: the UE sends its RRC Connection Message UL to base station A on that station's RACH, but this UE is near the border of two other cells controlled by respective base stations B and C. Base station A would like to have the UE's neighbor cell measurements from those other cells so it can make timely and proper decisions for handing over the UE. While the UE also sends neighbor cell measurements at other times and on other channels once the UE is in a RRC-Connected state for routine mobility, base station A would like to have those measurements as soon as the UE attempts access on the RACH so base station A can re-direct the UE's RRC connection to another neighbor base station if that neighbor is more appropriate for the requesting UE.
UEs which support features from 3GPP Release 7 and onwards support neighbor cell measurements for both inter-frequency and intra-frequency neighbors of the RACH base station. For such a UE the network/base station A would require the UE to send measured results on the RACH for both those types of neighbors, but this would exceed the RACH message size limit
To resolve this issue, current 3GPP specifications require the UE to check the message size, and if exceeded the UE shall omit RACH measured results starting with inter-frequency results. Specifically, subclause 8.5.23 of 3GPP TS 25.331 V10.0.0 states (emphasis added):                1> for messages transmitted on CCCH, take care that the maximum allowed message size is not exceeded when forming the IE “Measured results on RACH”, i.e. limit the number of included neighbour cells or if required omit the IE “Measured results on RACH” altogether. When limiting the number of included neighbouring cells, the number of inter-frequency cells should be limited first i.e. inter-frequency cells should be omitted before limiting the number of intra-frequency cells.        
In relevant teachings, document R2-104524 which is a Change Request for TR 25.331 V10.0.0 entitled “ADDITION OF OPTIMISED RACH MESSAGE TYPES” (3GPP TSG-RAN WG2 Meeting #71; Madrid, Spain; 23-27 Aug. 2010; by Nokia Corporation and Nokia Siemens Networks) introduce a new RACH message type which removes the non-critical extension indicators in abstract syntax notation asn1. But the message space saved with this new RACH message type is not enough to allow the UE to include neighbor cell measurements for both inter-frequency and intra-frequency neighbors in its UL RACH message.
The inventors consider the current approach in 3GPP as static approach and overly limiting, whereas the new RACH message noted above is not a solution either. The exemplary embodiments presented below resolve the above problems to a much greater extent than either the current 3GPP solution or the new RACH message type.